From Nietzsche's The Gay Science. Aphorism 110-
Those exceptional thinkers, like the Eliatics, who still posited and clung to the opposites of natural errors, believed in the possibility of also living this opposite: They invented the sage as a man of unchangeability, impersonality, universality of intuition, as one and all at the same time, with a special capacity for that inverted knowledge; they had at the faith that their knowledge was at the same time the principle of life. But in order to claim all this, they had to deceive themselve's about their own state.